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Science Final
7th grade Overall science
Term | Definition |
---|---|
The number of _______ in an atom determines the type of element you have. | Protons |
What are the elements in the periodic table arranged according to? | Their atomic number |
What kind of element are most of the elements on the periodic table? | Metals |
What is a characteristic of Transition metals? | They are conductors of electricity and heat |
If two charges repel each other, the two charges must be... | Like charges |
How does an object become charged? | When the atom gains or looses electrons |
What is static electricity? | Electric charge that has built up in one place |
What is an insulator? | A material through which electrons don't flow easily |
A positively charged object has... | More protons than electrons or neutrons (when it looses electrons) |
A magnet attracts to objects containing... | Iron |
On a bar magnet, which side would attract to the North side on another magnet? | The south side of the magnet |
In a battery, the energy is usually stored in the form of... | Chemical Energy |
What is PE? | Stored energy |
The thermal energy of a substance changes the ______ energy of its particles | Kinetic |
In every energy conversion, some energy is always converted into... | Thermal energy |
What does gravitational potential energy depend on? | Height and weight |
What does kinetic energy depend on? | Mass and velocity |
What energy conversion is taking place in a green plant in sunlight during the process of photosynthesis? | Light -> Chemical -> Thermal |
What sequence of energy transformations occurs after a battery operated flashlight is turned on? | Chemical -> Electrical -> Light -> Thermal |
After an energy conversion, you end up with the same total amount of energy as the original amount of PE. What law explains this rule? | Law of Conservation of Energy |
What is the density of water? | 1g/mL |
Which unit do you measure mass in? | Grams |
What is the standard unit of length? | Meters |
A student measures the mass of an empty graduated cylinder as 42g, she then measures a graduated cylinder filled with water and finds it has a mass of 62g. What is the mass of the water? | 62-42=20g |
In a graduated cylinder containing several liquid layers, the least dense liquid is found... | On the top |
If you have 150g of pure gold and the entity of the gold is 19.32g/cm cubed, what is the volume of your gold nugget? | V= M/D V= 7.8cm cubed |
What is the best way to measure the volume of an irregularly shaped solid? | Doing the water displacement method |
What happens to a solid object with a density that is less that water when it is placed in water? | It floats |
What is the solute? | The substance being dissolved in a solution |
What would be the best method in separating sand and iron? | Using a magnet |
What can you do to dissolve sugar fast? | Crush it, heat up the water, or stir the water with the sugar |
If a spoonful of salt is mixed into a glass of water, what is the water called? | A solvent |
What is the compound made by plants during photosynthesis? | Glucose |
Melting crayons is an example of what kind of change? | Physical change |
What chemical property is responsible for iron rusting? | Reactivity with Oxygen |
Malleability is and example of what kind of property? | Physical |
What is a compound? | A pure substance that is made up of two or more chemically combined elements |
Boiling point, melting point, and density are examples of an element's... | Physical properties |
By what process can compounds be broken down? | By chemical changes |
What happens to the properties of the different components of a mixture win materials combine? | They stay the same |
What is velocity? | The speed of an object in a particular direction |
To find the average speed of an object what do you need to know? | Total distance & total time |
A child on a merry go round is accelerating because the child is... | Changing direction |
If the mass of an object increases, the weight of the object will... | Increase |
Brakes in a bike work by pressing brake pads together on the rim of the wheels. The pads rub together and slow the bike, this is due to... | Friction (sliding friction) |
What is the speed of an object that covers 400km in 5 hrs? | S=D/T S=80km/hr |
The wheels and gears of a machine are greased in order to decrease... | FRICTION |
Why does friction occur? | No surface is completely smooth (there is always hills & mountains) |
What would happen to your weight if you went to the moon? | You would weigh less because there is less gravity |
An object in motion with no unbalanced force acting on it will... | Stay in motion |
If the force acting on an object increased and mass stayed the same, acceleration would.. | Increase |
What force causes a leaf to fall more slowly than a penny? | Air resistance |
All objects resist change in motion. This is the law of... | Inertia |
The statement "to every action there is an equal and opposite reaction" is: | Newton's Third Law |
When two objects collide, the momentum of the pair after the collision is explained by: | Newton's Third Law |
The shape of the path of a projectile motion is... | Curved |
What is a screw? | An inclined plane wrapped around a cylindrical pole |
The amount of work done by a machine is never larger than the work put into a machine because some of the input work is lost due to... | Friction |
Levers are divided into classes based on the location of their... | Fulcrum, load (output) and effort (input) |
When a soccer ball is kicked, why don't the action and reaction forces cancel each other out? | The forces don't work on the same object. |
Your acceleration increases as the force acting on you... | Increases |
The Moon's gravitational force has a greater affect on the ocean tides of Earth than the Sun's gravitational force. What is the reason for this? | The moon is closer to the Earth than the Sun. As distance increases, gravity decreases (indirect) |
What does the force of gravity depend on? | Distance and mass |
During which two changes of state do atoms or molecules become closer together? | Freezing and condensation |
Dew collection on a spider web is an example of what? | Condensation |
Which changes of state of water both occur at 100 degrees Celsius? | Boiling and Condensation |
What is sublimation? | When a solid changes directly into a gas. |
What best describes the particles of a solid? | Vibrate in place and close together |
Is liquid freezing endothermic or exothermic? | Exothermic |
What would happen to a balloon when you walk outside on a cold day? | It will deflate. Charle's Law, as temperature decreases, volume decreases, direct relationship |
What will happen to a gas when pressure decreases? | The volume will increase. Boyle's Law, as pressure increases, volume decreases, indirect relationship. |
Which substance has particles close together but slide past each other? | A liquid |
Which state of matter has definite shape and definite volume? | A solid |
During which three phase changes os heat energy absorbed by a substance? | Melting, boiling, and sublimation |
What is the reverse of condensation? | Vaporization |
According to Charle's Law... | As temperature increases, volume of a gas increases DIRECT RELATIONSHIP |
According to Boyle's Law... | As pressure of gas increases, volume decreases INDIRECT RELATIONSHIP |
During which change of state do atoms or molecules become more ordered? | Freezing |
What is a plasma? | A gas-like mixture with a volume and a shape that changes that is made up of charged particles (ions) |
As a sample of matter is heated its particles, | Move faster |
What is the fixed point in a lever? | The fulcrum |
What are the three ways a machine can make work easier for you? | 1) Change side of force 2) Change direction of force 3) Change distance the force is moved |
What does a fixed pulley change? | The direction of force |
How does using a ramp make lifting a heavy object easier? | YOu use the same amount of force but over a large distance. |